why i bought it?

[Gustav]

You could,no need though unless you want adjustable front/rear bias.Total overkill in terms of braking power to use both,if you can disable the esc brakes you can use just mechanical,more weight and clutter though.

saves a bit of stress on the esc but it's not really worth it unless you really prefer mechanical brakes or the car really needs the bias adjustment.

If you really need the bias adjustment i'd use mechanical brake on the front outdrive only and still use the esc brakes aswell,i think the rear brake and linkage would probably get in the way of the motor. Then just use the linkage and EPA to adjust the bias.Won't cause any problems for the esc but you need to find the space.